Circuit 9: Josephson Junction I-V Curve

    WRspice jj I-V curve demo
    *
    * One can plot a pretty decent iv curve using transient analysis.
    * This will show the differences between the various model options.
    *
    b1 1 0 jj1 control=v2
    v1 2 0 pwl(0 0 2n 70m 4n 0 5n 0)
    r1 2 1 100
    *
    * for rtype=4, vary v2 between 0 and 1 for no gap to full gap
    v2 3 0 .5
    *
    r2 3 0 1
    *
    * It is interesting to set rtype and delv to different values, and note
    * the changes.
    *
    *Nb 1000 A/cm2   area = 30 square microns
    .model jj1 jj(rtype=4,cct=1,icon=10m,vg=2.8m,delv=.1m,
    + icrit=0.3m,r0=100,rn=5.4902,cap=1.14195p)
    .tran 5p 5n
    * type "run", then "plot -b v(1) (-v1#branch)"
    .end